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24 Cards in this Set
- Front
- Back
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How do methotrexate and 5-FU differ from 6-mercaptopurine ?
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6-MP blocks purine synthesis whereas methotrexate and 5-FU block thymidine synthesis.
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What is 5-FU used for?
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colon cancer, basal cell carcinoma
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What is leucovorin used to reverse?
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Myelosuppression secondary to MTX. (NB: myelosuppression casued by 5-FU is NOT REVERSIBLE).
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We know that MTX and 5-FU both interfere with dTMP synthesis. How do they act differently?
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MTX interfers with dihydrofolate reductase, which is needed for tetrahydrofolate production. 5-FU blocks thymidylate synthase, which is further down the pathway, and is needed for dTMP production from dUMP.
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What other drug blocks dihydrofolate reductase? What is it used for?
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Trimethoprim. UTIs.
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Why are patients receiving 6-MP at increased risk of adverse effects if also taking allopurinol?
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6-MP is a purine analog metabolized by xanthine oxidase, which is inhibited by allopurinol in the treatment of gout.
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What does HGPRT do?
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HGPRT is involved in purine metabolism and thus activates 6-MP. HGPRT deficiency results in kidney stones, gout and mental retardation (delayed development). PRPP and uric acid are involved in this disease process.
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What are patients given for ALL?
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6-TG. Unlike 6-MP, can be given with allopurinol.
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What are patients given for CLL?
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CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone)
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What are patients given for AML or ALL?
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6-MP and Cytarabine. SE: Leukopenia, thrombocytopenia, megaoloblastic anemia.
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What is used to treat Wilms' tumor?
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Dactinomycin (mechanism: intercalates in DNA).
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What is used to treat Hodgkin's lymphomas?
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Doxorubicin (mechanism: free radicals).
Adriamycin is another name for the drug. Also, ABVD: Adriamycin, Bleomycin, Vinblastine, Dacarbazine). |
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What is used to treat testicular cancer?
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Bleomycin or Etoposide
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What is Bleomycin's mechanism of action?
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It is similar to Adriamycin: free radical generation causes double-stranded DNA breaks.
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Name two topoisomerase inhibitors.
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Etoposide (topo-II) and irinotecan (topo-I)
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What is the mechanism of action of cyclophosphamide?
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Covalently X-link DNA at guanines. Requires bioactivation by liver.
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What is used to treat brain tumors?
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Nitrosoureas (carmustine, lomustine, semustine, streptozocin).
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What is used to treat CML?
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Busulfan (alkylatesDNA).
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What two drugs are microtubule inhibitors?
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Vincristine and Paclitaxel.
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Vincristine side effects
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neurotoxicity
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Cisplatin, Carboplatin mechanism
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cross-link DNA
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Hydroxyura mechanism
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Inh ribonucleotide reductase
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Prednisone side effects
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cushing-like symptoms, peptic ulcers, osteoporosis, immunosuppression.
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Tamoxifen side effects
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Increased risk of endometrial carcinoma
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